1. Field of the Invention
The invention relates to apparatus of the crane type with a jib having articulated or telescopic arms for lifting or handling loads with a grab, winch-hook or hook. It relates more particularly to a device for automatically balancing the jib of such cranes depending on the variation of the radius or reach of this jib.
2. Description of the Prior Art
In known apparatus of this kind, the crane jib is generally articulated to the turret , without balancing, the counterweight itself being fixed to the turret. In this case, the counterweight in fact only serves for reducing the reversing moment but by a fixed value and without compensation as a function of the reach of the jib. Moreover, actuation cylinders for lifting the main arm or the auxiliary arm must lift at one and the same time the load, the jib and the member grasping the load.